Solid-state image sensor, imaging device, and electronic equipment

ABSTRACT

In a configuration in which a plurality of pixels are arranged with respect to at least either of one of the OCCFs or one of the OCLs, a floating diffusion (FD) is shared by a sharing unit including a plurality of pixels, the plurality of pixels including pixels of at least either of different OCCFs or different OCLs. The present technology is applicable to a CMOS image sensor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit under 35U.S.C. § 120 of U.S. patent application Ser. No. 15/812,179, titled“SOLID-STATE IMAGE SENSOR, IMAGING DEVICE, AND ELECTRONIC EQUIPMENT,”filed on Nov. 14, 2014, now U.S. Pat. No. 10,128,300, which is acontinuation of U.S. patent application Ser. No. 15/630,032, titled“SOLID-STATE IMAGE SENSOR, IMAGING DEVICE, AND ELECTRONIC EQUIPMENT,”filed on Jun. 22, 2017, now U.S. Pat. No. 9,865,643, which is acontinuation of U.S. patent application Ser. No. 15/395,538, titled“SOLID-STATE IMAGE SENSOR, IMAGING DEVICE, AND ELECTRONIC EQUIPMENT,”filed on Dec. 30, 2016, now U.S. Pat. No. 9,773,835, which is acontinuation of International Application No. PCT/JP2016/058452, filedMar. 17, 2016, which claims priority to Japanese Patent Application JP2015-072981, filed Mar. 31, 2015, each of which is hereby incorporatedby reference in its entirety.

TECHNICAL FIELD

The present technology relates to a solid-state image sensor, an imagingdevice, and electronic equipment. The present technology particularlyrelates to a solid-state image sensor, an imaging device, and electronicequipment configured such that an FD is shared by a plurality of pixelsto further miniaturize the pixels at low cost without lowering ofsensitivity and a conversion efficiency.

BACKGROUND ART

In a complementary metal oxide semiconductor (CMOS) image sensor calleda “dual pixel,” a plurality of pixels (photo diodes) (hereinaftersometimes simply referred to as a “PD”) sharing an on-chip lens(hereinafter sometimes simply referred to as an “OCL”) shares the samefloating diffusion (hereinafter sometimes simply referred to as an“FD”).

More specifically, the CMOS image sensor called the “dual pixel” has thestructure of sharing an FD by two pixels. In such an image sensor,transfer gates (hereinafter sometimes simply referred to as “TRGs”) oftwo pixels are arranged adjacent to each other, and a polysilicon(Poly-Si) gate has a two-layer structure. With such a structure,narrowing of an FD region and expansion of a PD region can be realized,and as a result, sensitivity and a saturation signal amount (hereinaftersometimes referred to as a “Qs”) can be improved.

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2004-319837

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, in the above-described CMOS image sensor called the “dualpixel,” the FD is shared only by the pixels sharing the OCL, and forthis reason, more miniaturization of a pixel size results in a lowerdegree of freedom in a layout.

In the case of closely arranging pixels in the front-end-of-line (FEOL)layout of the substrate surface on which elements are arranged, themaximum PD region is ensured, and for this reason, it is inevitable toreduce the width (the L length) of an amplification transistor(hereinafter sometimes referred to as an “AMP transistor”). This mightlead to worsening of random noise.

On the other hand, in order to avoid worsening of the random noise, itis inevitable to narrow the PD region. This might lead to lowering ofsensitivity and a Qs.

Further, in order for the back-end-of-line (BEOL) layout of thesubstrate surface on which wiring is made to accept high dynamic range(HDR) driving, the number of control lines is higher, and it is moredifficult to arrange such control lines.

Moreover, in the case of requiring a plurality of vertical signal lines(hereinafter sometimes simply referred to as “VSLs”) to realizehigh-speed reading, the spacing between adjacent ones of the VSLs needsto be small, and for this reason, the influence of parasitic capacitancedue to a capacitive coupling between adjacent ones of the VSLs becomesgreater.

In addition, although the number of line layers may be increased for theabove-described purposes, not only a cost increases due to such anincrease in the number of line layers, but also parasitic capacitancedue to a capacitive coupling between a FD line and a peripheral lineincreases by a complicated layout of the FD line. For these reasons, aconversion efficiency might be lowered.

The present technology has been made in view of the above-describedsituation, and particularly intended to further miniaturize pixels atlow cost by sharing of a OCCF by a plurality of pixels without loweringof sensitivity and a conversion efficiency.

Solutions to Problems

A solid-state image sensor of one aspect of the present technologyincludes at least either of on-chip color filters (OCCFs) configured toextract light having a predetermined wavelength from incident light oron-chip lenses (OCLs) configured to collect the incident light, photodiodes configured to use, as incident light, light extracted from atleast either of the light collected by the OCCFs or the OCLs and havingthe predetermined wavelength to generate, for each pixel unit, chargecorresponding to the amount of the incident light by a photoelectriceffect, and a floating diffusion (FD) configured to accumulate thecharge generated by the photo diodes to apply voltage corresponding tothe accumulated charge to a gate of an amplification transistor. In aconfiguration in which a plurality of pixels are arranged with respectto at least either of one of the OCCFs or one of the OCLs, the FD isshared by a sharing unit including a plurality of pixels, the pluralityof pixels including pixels of at least either of different OCCFs ordifferent OCLs.

The photo diodes of two pixels may be arranged with respect to at leasteither of one of the OCCFs or one of the OCLs.

The sharing unit may include the pixels corresponding to at least eitherof the OCCFs or the OCLs adjacent to each other in a horizontaldirection.

The sharing unit may include the pixels corresponding to at least anyones of two OCCFs, four OCCFs, two OCLs, and four OCLs adjacent to eachother in the horizontal direction.

The sharing unit may include the pixels corresponding to at least eitherof the OCCFs or the OCLs adjacent to each other in a vertical direction.

The sharing unit may include the pixels corresponding to at least anyones of two OCCFs, four OCCFs, two OCLs, and four OCLs adjacent to eachother in the vertical direction.

The sharing unit may include the pixels corresponding to at least eitherof the OCCFs or the OCLs adjacent to each other in horizontal andvertical directions.

The sharing unit may include the pixels corresponding to at least eitherof the OCCFs or the OCLs adjacent to each other such that there are twoOCCFs or two OCLs in the horizontal direction and two OCCFs or two OCLsin the vertical direction.

The sharing unit may include the pixels corresponding to at least eitherof the OCCFs or the OCLs extracting light having an identicalwavelength.

The solid-state image sensor may further include: a reset transistor; atransfer transistor; and the amplification transistor.

The solid-state image sensor may further include: a reset transistor; atransfer transistor; the amplification transistor; a selectiontransistor.

A dummy transistor may be disposed at such a position that arrangementintervals with respect to the reset transistor, the amplificationtransistor, and the selection transistor are in symmetrical positions inan arrangement direction of the reset transistor, the amplificationtransistor, and the selection transistor.

The solid-state image sensor may further include: a vertical signal lineconfigured to transfer a pixel signal output from the amplificationtransistor, and the vertical signal line may be shared by the sharingunits.

A source/drain may be shared by the sharing units.

An imaging device of another aspect of the present technology includesat least either of on-chip color filters (OCCFs) configured to extractlight having a predetermined wavelength from incident light or on-chiplenses (OCLs) configured to collect the incident light, photo diodesconfigured to use, as incident light, light extracted from at leasteither of the light collected by the OCCFs or the OCLs and having thepredetermined wavelength to generate, for each pixel unit, chargecorresponding to the amount of the incident light by a photoelectriceffect, and a floating diffusion (FD) configured to accumulate thecharge generated by the photo diodes to apply voltage corresponding tothe accumulated charge to a gate of an amplification transistor. In aconfiguration in which a plurality of pixels are arranged with respectto at least either of one of the OCCFs or one of the OCLs, the FD isshared by a sharing unit including a plurality of pixels, the pluralityof pixels including pixels of at least either of different OCCFs ordifferent OCLs.

Electronic equipment of another aspect of the present technologyincludes: at least either of on-chip color filters (OCCFs) configured toextract light having a predetermined wavelength from incident light oron-chip lenses (OCLs) configured to collect the incident light; photodiodes configured to use, as incident light, at least either of thelight having the predetermined wavelength and extracted by the OCCFs orthe light collected by the OCLs to generate, for each pixel unit, chargecorresponding to an amount of the incident light by a photoelectriceffect; and a floating diffusion (FD) configured to accumulate thecharge generated by the photo diodes to apply voltage corresponding tothe accumulated charge to a gate of an amplification transistor, and ina configuration in which a plurality of pixels are arranged with respectto at least either of one of the OCCFs or one of the OCLs, the FD isshared by a sharing unit including a plurality of pixels, the pluralityof pixels including pixels of at least either of different OCCFs ordifferent OCLs.

According to such aspects of the present technology, the light havingthe predetermined wavelength is extracted from the incident light by atleast either of the on-chip color filters (OCCFs) or the on-chip lenses(OCLs) configured to collect the incident light. The photo diodes use,as the incident light, at least either of the light extracted by theOCCFs and having the predetermined wavelength or the light collected bythe OCLs to generate, for each pixel unit, the charge corresponding tothe amount of the incident light by the photoelectric effect. Thefloating diffusion (FD) accumulates the charge generated by the photodiodes to apply the voltage corresponding to the accumulated charge tothe gate of the amplification transistor. The FD is shared by a sharingunit including the plurality of pixels, the plurality of pixelsincluding a set of pixels being arranged corresponding to at least oneof the OCCFs or OCLs and another set of pixels being arrangedcorresponding to at least another one of the OCCFs or OCLs.

Effects of the Invention

According to the aspects of the present technology, an FD is shared bythe plurality of pixels, and therefore, the pixels can be furtherminiaturized at low cost without lowering of sensitivity and aconversion efficiency.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram for describing a circuit configuration example of a3Tr. type solid-state image sensor to which the present technology isapplied.

FIG. 2 is a diagram for describing a circuit configuration example of a4Tr. type solid-state image sensor to which the present technology isapplied.

FIG. 3 is a diagram for describing a circuit configuration example of asolid-state image sensor configured such that an FD is shared by aplurality of pixels.

FIG. 4 is a view for describing the layout of a configuration example ofa first embodiment of the solid-state image sensor to which the presenttechnology is applied.

FIG. 5 is a view for describing the back-end-of-line (BEOL) layout ofthe solid-state image sensor of FIG. 4.

FIG. 6 is a view for describing the layout of a plurality of verticalsignal lines of the solid-state image sensor of FIG. 4.

FIG. 7 is a view for describing the layout of a configuration example ofa second embodiment of the solid-state image sensor to which the presenttechnology is applied.

FIG. 8 is a view for describing the layout of a configuration example ofa third embodiment of the solid-state image sensor to which the presenttechnology is applied.

FIG. 9 is a view for describing the layout of a configuration example ofa fourth embodiment of the solid-state image sensor to which the presenttechnology is applied.

FIG. 10 is a view for describing the layout of a configuration exampleof a fifth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 11 is a view for describing the layout of a configuration exampleof a sixth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 12 is a view for describing the layout of a configuration exampleof a seventh embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 13 is a view for describing the layout of a configuration exampleof an eighth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 14 is a view for describing the layout of a configuration exampleof a ninth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 15 is a view for describing the layout of a configuration exampleof a tenth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 16 is a view for describing the layout of a configuration exampleof an eleventh embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 17 is a view for describing the layout of a configuration exampleof a twelfth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 18 is a view for describing the layout of a configuration exampleof a thirteenth embodiment of the solid-state image sensor to which thepresent technology is applied.

FIG. 19 is a diagram for describing the configuration of an imagingdevice and electronic equipment using the solid-state image sensor towhich the present technology is applied.

FIG. 20 is a diagram of use examples of the solid-state image sensor.

MODE FOR CARRYING OUT THE INVENTION

Examples of the mode for carrying out the present invention will bedescribed below, but the present invention is not limited to theexamples below.

First Embodiment

<Circuit Configuration Example of 3Tr. Type Solid-State Image Sensor>

FIG. 1 illustrates a circuit configuration example of a pixel unitforming a solid-state image sensor to which the present technology isapplied.

The circuit configuration example of a pixel P of the solid-state imagesensor of FIG. 1 includes a reset transistor TR1, a transfer transistorTR2, an amplification transistor TR3, a floating diffusion FD(hereinafter sometimes simply referred to as an “FD”), a photo diode PD(hereinafter sometimes simply referred to as a “PD”), and a verticalsignal line VSL.

Since the solid-state image sensor with the configuration of FIG. 1 is asolid-state image sensor including three transistors in total, i.e., thereset transistor TR1, the transfer transistor TR2, and the amplificationtransistor TR3. Thus, such a solid-stage image sensor is a solid-stateimage sensor called a “3Tr. type.”

The PD is configured to generate, by photoelectric conversion, chargecorresponding to the amount of incident light and accumulate thegenerated charge.

The transfer transistor TR2 is a transistor configured to open/closeaccording to a transfer signal applied to a gate. When the transfersignal is at a high level, the transfer transistor TR2 is turned ON totransfer the charge accumulated in the PD to the FD.

Electrons are also accumulated in the FD according to the number ofelectrons transferred from the PD. Moreover, the potential of the FD isapplied to a gate of the amplification transistor TR3.

The reset transistor TR1 is a transistor configured to open/closeaccording to a reset signal TR1. When the reset transistor TR1 is ON,the charge accumulated in the FD is output to a drain terminal D1.

The amplification transistor TR3 is a transistor configured toopen/close according to an amplification control signal. Theamplification transistor TR3 uses input voltage corresponding to thecharge accumulated in the FD to amplify voltage applied from a drainterminal D2, and then, outputs the amplified voltage as a pixel signalto the vertical signal line VSL.

That is, the PD and the FD are reset in such a manner that the resettransistor TR1 and the transfer transistor TR2 are turned ON.

Subsequently, turning OFF of the transfer transistor TR2 brings about aPD exposure state. Accordingly, the charge corresponding to the amountof incident light is, by photoelectric conversion, generatedsequentially in the PD, and then, is accumulated in the PD.

In such a state, when the transfer transistor TR2 is turned ON, thecharge accumulated in the PD is transferred to the FD.

At this point, when the voltage corresponding to the charge accumulatedin the PD is input to the gate of the amplification transistor TR3, theamplification transistor TR3 amplifies the voltage applied from thedrain terminal D2 to output the amplified voltage as the pixel signal tothe vertical signal line VSL.

Subsequently, similar operation is repeated to output the pixel signalat predetermined time intervals.

<Circuit Configuration Example of 4Tr. Type Solid-State Image Sensor>

Next, a circuit configuration example of a 4Tr. type solid-state imagesensor will be described with reference to FIG. 2.

The circuit configuration example of a pixel P of the 4Tr. typesolid-state image sensor includes a reset transistor TR11, a transfertransistor TR12, an amplification transistor TR13, a selectiontransistor TR14, an FD, a PD, and a vertical signal line VSL.

The reset transistor TR11, the transfer transistor TR12, theamplification transistor TR13, the floating diffusion FD, the PD, andthe vertical signal line VSL have the same functions as those of thereset transistor TR1, the transfer transistor TR2, the amplificationtransistor TR3, the floating diffusion FD, the PD, and the verticalsignal line VSL in FIG. 1, except for the selection transistor TR14.Thus, description of these sections will not be repeated.

That is, the 4Tr. type solid-state image sensor of FIG. 2 is asolid-state image sensor including four transistors, i.e., the resettransistor TR11, the transfer transistor TR12, the amplificationtransistor TR13, and the selection transistor TR14. Thus, such asolid-stage image sensor is called a “4Tr. type.”

The selection transistor TR14 is a transistor configured to open/closeaccording to a selection signal applied to a gate. When the selectionsignal is at a high level, the selection transistor TR14 is turned ON,and then, a pixel signal output according to the voltage of the FDapplied to a gate of the amplification transistor TR13 is output to thevertical signal line VSL.

That is, in the case of the 4Tr. type solid-state image sensor, a pixelsignal of a selected pixel P is output by the selection transistor TR14.

<FD Sharing by Pixels>

Next, a circuit configuration example in the case of sharing an FD by aplurality of pixels will be described with reference to FIG. 3.

FIG. 3 illustrates the circuit configuration example where transfertransistors TR12-1 to TR12-8 each coupled to a cathode of acorresponding one of PD 1 to PD 8 between a source and a drain areprovided for the same FD.

That is, FIG. 3 illustrates the circuit configuration in which eightpixels of the PD 1 to PD 8 shares the FD.

With such a configuration, the FD can be used for a pixel of the PD 1 insuch a manner that the transfer transistor TR12-1 is controlled to ON orOFF with the transfer transistors TR12-2 to TR12-8 being OFF, forexample. Thus, in the circuit configuration of the solid-state imagesensor of FIG. 3, ON/OFF of the transfer transistors 12-1 to 12-8 iscontrolled so that the FD can be switched and used for each of the PD 1to PD 8. In the present embodiment, an FD (including the resettransistor TR11, the transfer transistor TR12, the amplificationtransistor TR13, the selection transistor TR14, and the vertical signalline VSL) can be shared by eight pixels.

For example, as illustrated in the region surrounded by a dashed line inFIG. 3, the configuration including the transfer transistors TR12-1,TR12-2 and the PD 1, PD 2 in addition to the reset transistor TR11, thetransfer transistor TR12, the amplification transistor TR13, theselection transistor TR14, and the vertical signal line VSL realizestwo-pixel sharing, i.e., sharing of the FD by two pixels of the PD 1, PD2.

Moreover, as illustrated in, e.g., the region surrounded by a chain linein FIG. 3, the configuration including the transfer transistors TR12-1to TR12-4 and the PD 1 to PD 4 in addition to the reset transistor TR11,the transfer transistor TR12, the amplification transistor TR13, theselection transistor TR14, and the vertical signal line VSL realizesfour-pixel sharing, i.e., sharing of the FD by four pixels.

Further, as illustrated in, e.g., the region surrounded by a chaindouble-dashed line in FIG. 3, the configuration including the transfertransistors TR12-1 to TR12-8 and the PD 1 to PD 8 in addition to thereset transistor TR11, the transfer transistor TR12, the amplificationtransistor TR13, the selection transistor TR14, and the vertical signalline VSL realizes eight-pixel sharing, i.e., sharing of the FD by eightpixels.

Further, the number of PDs other than above can be coupled to a commonFD via transfer transistors.

With such a configuration, in further pixel miniaturization, theaperture ratio of the PD can be improved, and pixel miniaturization canbe made without lowering of sensitivity and a decrease in a saturationsignal amount Qs.

Moreover, the vertical signal line VSL can be shared by a plurality ofpixels, but there is a concern on signal interference due to acapacitive coupling between the vertical signal lines VSL. That is, inthe case where there are adjacent vertical signal lines VSL1, VSL2 closeto each other, when an output signal of the vertical signal line VSL1 ispresent and an output signal of the vertical signal line VSL2 is absent,there is a concern that the output signal of the vertical signal lineVSL1 is on the vertical signal line VSL2 and is detected as a falsesignal. On the other hand, sharing of the vertical signal line VSL bythe plurality of pixels can ensure a sufficient space between adjacentones of the vertical signal lines VSL. As a result, the L length of theamplification transistor (AMP) TR13 can be ensured, and worsening ofrandom noise can be suppressed.

Note that the 4Tr. type solid-state image sensor has been described asan example with reference to FIG. 3, and needless to say, the circuitconfiguration of the 3Tr. type solid-state image sensor is applicable.Moreover, the group of a plurality of pixels sharing and using an FD asdescribed above is hereinafter referred to as a sharing unit. Thus, inFIG. 3, the region surrounded by the dashed line is the sharing unit forrealizing two-pixel sharing, the region surrounded by the chain line isthe sharing unit for realizing four-pixel sharing, and the regionsurrounded by the chain double-dashed line is the sharing unit forrealizing eight-pixel sharing.

<Layout in Sharing of FD by 4Tr. Type Pixels of 4×2>

Next, the layout of a solid-state image sensor formed of afront-end-of-line (FEOL) backside illumination type complementary metaloxide semiconductor (CMOS) image sensor in the case where an FD isshared by 4Tr. type pixels of 4×2 will be described with reference toFIG. 4.

In FIG. 4, for each on-chip color filter (OCCF), twovertically-elongated PDs are arranged in the horizontal direction, andthese two PDs continuously arranged in the horizontal direction form asquare region.

More specifically, four OCCFs with a Bayer array of Gb, R, B, Gr areprovided in the order of the upper left side, the lower left side, theupper right side, the lower right side. For the OCCF for Gb, rectangularPD 1, PD 2 whose vertical length is longer than the horizontal lengthare provided. Similarly, the OCCF for R is provided with PD 3, PD 4, theOCCF for B is provided with PD 5, PD 6, and the OCCF for Gr is providedwith PD 7, PD 8.

That is, in FIG. 4, a common FD is provided for the total of eightpixels, each of the total of four OCCFs of two in the horizontaldirection×two in the vertical direction being provided with two pixelsarranged in the horizontal direction. These eight pixels form thesharing unit for the FD.

Transfer transistors TR12-1 to TR12-4 are provided respectively at thecorners of the PD 1 to PD 4 such that the corners respectively contactthe positions of a square terminal T1 facing the corners, the squareterminal T1 being provided at a center position of the boundary betweenthe OCCFs for Gb, R and being coupled to the FD. Similarly, transfertransistors TR12-5 to TR12-8 are provided respectively at the corners ofthe PD 5 to PD 8 such that the corners respectively contact thepositions of a square FD (T2) facing the corners, the square FD beingprovided at a center position of the boundary between the OCCFs for B,Gr.

Further, on the lower side as viewed in FIG. 4, the reset transistorTR11, the amplification transistor TR13, and the selection transistorTR14 coupled to a line coupled to the common terminals T1, T2 and the FDare provided in this order from the left side to extend across an S/D (asource/drain).

In addition, well contacts C1 to C3 are provided respectively at thecorners of the OCCFs at the boundary between each of two upper OCCFs andeach of two lower OCCFs.

The horizontal length of the amplification transistor TR13 as viewed inFIG. 4 can be increased by pixel sharing, and as a result, worsening ofrandom noise can be prevented. Further, since the FD is shared by theplurality of pixels covered by the plurality of OCCFs, a PD area can beexpanded. Thus, sensitivity characteristics can be improved, and asaturation signal amount Qs can be improved. Moreover, arrangement ofthe transfer transistors TR12-1 to TR12-4 and arrangement of thetransfer transistors TR12-5 to TR12-8 relative to the PDs and symmetryamong the reset transistor TR11, the amplification transistor TR13, andthe selection transistor TR14 can reduce photo response non-uniformity(PRNU).

Output is made from the same FD for Gr, Gb, and therefore, the signaldifference can be reduced.

For the back-end-of-line (BEOL) layout of the solid-state image sensorof FIG. 4, for example, when different exposure times are set for twoPDs of each OCCF and wiring is made to accept high dynamic range (HDR)driving for expanding a dynamic range, such wiring is as illustrated inFIG. 5.

More specifically, FIG. 5 illustrates the wiring when two sharing unitsare arranged in the horizontal direction, each sharing unit includingeight pixels of 4×2 sharing an FD. Each black circle in FIG. 5 indicatesthe point where each line is electrically coupled.

That is, the lines of FIG. 5 include, in the order from the upper side,a control signal line Sel for a selection transistor TR14; a powersupply line VDD; a transfer control signal line B2_R for a PD 6 of aright pixel of an OCCF for B in the right sharing unit surrounded by adashed line; a transfer control signal line B2_L for a PD 5 of a leftpixel of the OCCF for B in the right sharing unit; a transfer controlsignal line Gb_R for a PD 2 of a right pixel in each OCCF for Gb; atransfer control signal line Gb_L for a PD 1 of a left pixel in eachOCCF for Gb; a transfer control signal B1_R for a PD 6 of a right pixelof an OCCF for B in the left sharing unit; and a transfer control signalline B1_L for a PD 5 of a left pixel of the OCCF for B in the leftsharing unit.

Further, the lines below the above-described lines include, in the orderfrom the upper side, a transfer control signal line R2_R for a PD 4 of aright pixel of an OCCF for R in the right sharing unit; a transfercontrol signal line R2_L for a PD 3 of a left pixel of the OCCF for R inthe right sharing unit; a transfer control signal line Gr_R for a PD 8of a right pixel in each OCCF for Gr; a transfer control signal lineGr_L for a PD 7 of a left pixel in each OCCF for Gr; a transfer controlsignal line R1_R for a PD 4 of a right pixel of an OCCF for R in theleft sharing unit; a transfer control signal line R1_L for a PD 3 of aleft pixel of an OCCF for R in the left sharing unit; and a controlsignal line Rst for the reset transistor TR11.

That is, for the sharing units each including the pixels of 4×2 sharingthe FD, two types of connection patterns are alternately provided in thehorizontal direction.

Even in the case of requiring the above-described wiring, a verticaldistance corresponds to two pixels, and therefore, the degree of freedomin a layout can be increased. Further, although not shown in the figure,the source/drain may be also shared by a plurality of sharing units, andsimilar advantageous effects can be obtained.

Further, for the vertical signal line VSL, there is a spacecorresponding to four pixels in the horizontal direction (i.e.,corresponding to two pixels in the vertical direction). Thus, wiring ofa plurality of vertical signal lines VSL can be made. For example, in asharing unit including pixels of 4×2 as illustrated in FIG. 6, fourvertical signal lines VSL1 to VSL4 are provided, and a power supply lineVDD is provided at each end of the sharing unit. Further, a shield VSSis provided between adjacent ones of the vertical signal lines VSL, andtherefore, interference due to a capacitive coupling can be reduced.

Note that the configuration in which two PDs elongated in the verticaldirection are, for each OCCF, provided in the horizontal direction hasbeen described above. However, when such an OCCF is formed of a pixel, aPD can be utilized as a phase detection pixel (a ZAF pixel). That is,one of these two adjacent PDs elongated in the vertical direction can beutilized as a left light-shielded pixel whose left half is not shaded,and the other PD can be utilized as aright light-shielded pixel whoseright half is not shaded. Images acquired by these PDs shift to rightand left depending on a focal length. Thus, the image acquired by the PDcorresponding to the left light-shielded pixel and the image acquired bythe PD corresponding to the right light-shielded pixel coincident witheach other at a focal point, but a phase difference between these imagesis caused at a point shifted from the focal point depending on adifference in the focal length between the images. For this reason, thedifference in the focal length is obtained on the basis of the phasedifference, and therefore, the focal point can be adjusted at highspeed.

Second Embodiment

<Layout in Sharing of FD by 3Tr. Type Pixels of 4×2>

Next, a layout in the case where an FD is shared by 3Tr. type pixels of4×2 will be described with reference to FIG. 7. Note that in the layoutof a solid-state image sensor of FIG. 7, the same names and the samereference numerals are used to represent equivalent elements in aconfiguration having the same functions as those of the configuration inthe layout of the solid-state image sensor of FIG. 4, and descriptionthereof will be optionally omitted.

A circuit configuration of the 3Tr. type solid-state image sensor ofFIG. 7 is different from the circuit configuration of the 4Tr. typesolid-state image sensor in the presence or absence of a selectiontransistor TR14. Moreover, the reset transistor TR1, the transfertransistor TR2, and the amplification transistor TR3 in the 3Tr. typesolid-state image sensor of FIG. 1 are the same as the reset transistorTR11, the transfer transistor TR12, and the amplification transistorTR13 in the 4Tr. type solid-state image sensor. Thus, each of transfertransistors TR2-1 to TR2-8 of PD 1 to PD 8 of FIG. 7 is the same as acorresponding one of the transfer transistors TR12-1 to TR12-8 of FIG.4.

That is, in the case of the 3Tr. type solid-state image sensor of FIG.7, each of a reset transistors TR1 and an amplification transistor TR3is provided at the center of a lower end portion of a corresponding oneof OCCFs for R, Gr to extend across an S/D (a source/drain) on the lowerside as viewed in the figure. In the case of the 3Tr. type solid-stateimage sensor of FIG. 7, symmetry in component arrangement is higher thanthat in component arrangement of the 4Tr. type solid-state image sensorof FIG. 4. Thus, photo response non-uniformity can be further reduced.

Third Embodiment

<Layout in the Case of Providing Well Contacts Near Pixel Transistors in4Tr. Type Solid-State Image Sensor>

Next, the layout of a solid-state image sensor in the case of providingwell contacts near pixel transistors (a reset transistor TR1, TR11, anamplification transistor TR3, TR13, and a selection transistor TR14)will be described with reference to FIG. 8.

Note that in the layout of the solid-state image sensor of FIG. 8, thesame names and the same reference numerals are used to representequivalent elements in a configuration having the same functions asthose of the configuration in the layout of the solid-state image sensorof FIG. 4, and description thereof will be optionally omitted.

That is, the layout of the solid-state image sensor of FIG. 8 isdifferent from the layout of the solid-state image sensor of FIG. 4 inthat the well contacts are not arranged to extend across the space wherePD 1 to PD 8 are arranged, but are arranged near the reset transistorTR11, the amplification transistor TR13, and the selection transistorTR14.

That is, in FIG. 8, the reset transistor TR11, the amplificationtransistor TR13, and the selection transistor TR14 are provided betweenthe well contacts C1, C2.

In the layout illustrated in FIG. 8, the PD 1 to PD 8 are not arrangedbetween the well contacts C1, C2 in the horizontal direction. Thus,corrosion of the PD 1 to PD 8 due to diffusion in high-concentrationp-type implantation can be prevented, and therefore, a loss in asaturation signal amount Qs can be avoided.

Moreover, since the well contacts C1, C2 are arranged apart fromtransfer transistors TR12-1 to TR12-8, the well contacts C1, C2 can beless susceptible to an intense electric field generated due to turningON of the transfer transistors TR12-1 to TR12-8, and the risk of causingwhite spots due to such an intense electric field can be reduced.

Fourth Embodiment

<Layout in the Case of Providing Well Contacts Near Pixel Transistors in3Tr. Type Solid-State Image Sensor>

The layout of providing the well contacts near the pixel transistors inthe 4Tr. type solid-state image sensor has been described above, butwell contacts may be provided near pixel transistors in a 3Tr. typesolid-state image sensor.

FIG. 9 illustrates the layout of providing the well contacts near thepixel transistors in the 3Tr. type solid-state image sensor. Note thatin the layout of the solid-state image sensor of FIG. 9, the same namesand the same reference numerals are used to represent equivalentelements in a configuration having the same functions as those of theconfiguration in the layout of the solid-state image sensor of FIG. 8,and description thereof will be optionally omitted.

That is, in the layout of the 3Tr. type solid-state image sensor of FIG.9, the well contacts C1, C2 are also provided near a reset transistorTR1 and an amplification transistor TR3.

With such arrangement, reduction in a saturation signal amount Qs can besuppressed, and the risk of causing white spots can be reduced. Further,the width (the L length) of each pixel transistor in the horizontaldirection as viewed in the figure can be ensured.

Fifth Embodiment

<Layout of Solid-State Image Sensor in Sharing of FD by 4Tr. Type Pixelsof 2×4>

The example where the sharing unit for sharing the FD includes the totalof eight pixels of 4×2, i.e., the total of eight pixels using thedifferent OCCFs has been described above. However, other layout of aplurality of pixels forming a sharing unit than the above-describedlayout may be employed, and for example, the sharing unit for sharing anFD may include pixels of 2×4.

FIG. 10 illustrates the layout of a solid-state image sensor configuredsuch that each sharing unit for sharing an FD includes pixels of 2×4.

For each on-chip color filter (OCCF) in the layout of the solid-stateimage sensor of FIG. 10, two PDs elongated in the vertical directionare, as in the case of the layout of the solid-state image sensor ofFIG. 4, arranged in the horizontal direction, and these two PDscontinuously arranged in the horizontal direction form a square region.

More specifically, of the OCCFs with a Bayer array of Gb, R, B, Grprovided in the order of the upper left side, the lower left side, theupper right side, the lower right side, the OCCFs for Gb, R arrangedadjacent to each other in the vertical direction in the left column asviewed in the figure are repeated twice, and therefore, these four OCCFsin total form one of sharing units. Similarly, of the OCCFs with theBayer array of Gb, R, B, Gr provided in the order of the upper side, thelower left side, the upper right side, the lower right side, the twoOCCFs for B, Gr arranged adjacent to each other in the verticaldirection in the right column as viewed in the figure are repeated twicein a column at the right of the column of the OCCFs for Gb, R, andtherefore, these four OCCFs in total form the other sharing unit. Then,the column in which the one sharing unit repeatedly is arranged in thevertical direction and the column in which the other sharing unitrepeatedly is arranged in the vertical direction are alternatelyarranged.

Further, for the OCCF for Gb in one of the sharing units, rectangular PD1, PD 2 whose vertical length is longer than the horizontal length areprovided. Similarly, the OCCF for R is provided with PD 3, PD 4, thesecond OCCF for Gb below the OCCF for R is provided with PD 5, PD 6, andanother OCCF for R below the OCCF for second OCCF for Gb is providedwith PD 7, PD 8.

That is, in FIG. 10, the common FD is provided for the total of eightpixels, each of the total of four OCCFs of one in the horizontaldirection×four in the vertical direction being provided with two pixelsarranged in the horizontal direction.

Further, transfer transistors TR12-1 to TR12-4 are provided respectivelyat the corners of the PD 1 to PD 4 such that the corners respectivelycontact the positions of a square FD (T1) facing the corners, the squareFD being provided at a center position of the boundary between the upperOCCFs for Gb, R. Similarly, transfer transistors TR12-5 to TR12-8 areprovided respectively at the corners of the PD 5 to PD 8 such that thecorners respectively contact the positions of a square FD (T2) facingthe corners, the square FD being provided at a center position of theboundary between the lower OCCFs for Gb, R.

Further, at the boundary between the upper OCCF for R and the lower OCCFfor Gb, a selection transistor TR14 and an amplification transistor TR13are, in this order from the left side, provided to extend across an S/D(a source/drain), the transistors TR14, TR13 being coupled to a linecoupled to the common square FDs (T1, T2). Moreover, at the center ofthe boundary of the lower OCCF for R, a reset transistor TR11 isprovided to extend across an S/D.

In addition, each of well contacts C1, C2, C3, C4 is provided at acorresponding one of the corners of the OCCFs at the boundaries betweenthe upper OCCFs for Gb, R and between the lower OCCFs for Gb, R.

According to the configuration of the solid-state image sensor of FIG.10, it is difficult to ensure a length in the horizontal direction asviewed in the figure, and therefore, it is difficult to reduce theinfluence of random noise. However, a conversion efficiency can beimproved.

Moreover, in each sharing unit of the solid-state image sensor of FIG.10, the same FD is shared by two OCCFs for the same color. Thus, FDaddition is available for pixel signals of the pixels for the samecolor, and therefore, a dynamic range can be expanded. Further, as inthe configuration of the solid-state image sensor of FIG. 5, drive linesfor HDR driving can be easily arranged in a BEOL layout, and theinfluence of parasitic capacitance due to a capacitive coupling betweenthe drive lines can be reduced.

Sixth embodiment

<Layout of Solid-State Image Sensor Configured Such that FD is Shared by4Tr. Type Pixels of 2×4 and Source/Drain is Shared by Adjacent SharingUnits>

The example configuration in which the source/drain (S/D) isindependently provided for each sharing unit has been described above.In the case of the solid-state image sensor of FIG. 10, the horizontaldistance is fixed in sharing by pixels of 2×4, and therefore, the degreeof freedom in wiring of a plurality of vertical signal lines VSL isdetermined. Thus, in order to reduce random noise, an L length may beensured by sharing of a drain of an amplification transistor TR13.

FIG. 11 illustrates the layout of a solid-state image sensor configuredsuch that a source/drain (S/D) is shared by sharing units adjacent toeach other in the horizontal direction. Note that in the layout of thesolid-state image sensor of FIG. 11, the same names and the samereference numerals are used to represent equivalent elements in aconfiguration having the same functions as those of the configuration inthe layout of the solid-state image sensor of FIG. 10, and descriptionthereof will be optionally omitted.

That is, the layout of the solid-state image sensor of FIG. 11 isdifferent from the layout of the solid-state image sensor of FIG. 10 inthat the source/drain (S/D) is shared by the adjacent sharing unitsindicated by dashed lines. In association with sharing of thesource/drain (S/D) by the adjacent sharing units, arrangement of anamplification transistor TR13 and a selection transistor TR14 in theright sharing unit as viewed in FIG. 11 is inverted to right and left inthe case of FIG. 10.

As illustrated in the solid-state image sensor of FIG. 11, thesource/drain (S/D) is shared by the sharing units adjacent to each otherin the horizontal direction, and therefore, the L lengths of theselection transistor TR14 and the amplification transistor TR13 can beensured.

Seventh Embodiment

<Layout of Solid-State Image Sensor Configured Such that FD is Shared by4Tr. Type Pixels of 2×4 and Vertical Signal Line is Shared by adjacentsharing units>

The layout in which the source/drain (S/D) is shared by adjacent sharingunits has been described above, but a vertical signal line may be sharedby sharing units adjacent to each other in the horizontal direction.

FIG. 12 illustrates the layout of a solid-state image sensor configuredsuch that a vertical signal line is shared by sharing units adjacent toeach other in the horizontal direction. Note that in the layout of thesolid-state image sensor of FIG. 12, the same names and the samereference numerals are used to represent equivalent elements in aconfiguration having the same functions as those of the configuration inthe layout of the solid-state image sensor of FIG. 11, and descriptionthereof will be optionally omitted.

That is, in the layout of the solid-state image sensor of FIG. 12, anot-shown vertical signal line VSL is provided to vertically extend inthe vicinity of a center position in the horizontal direction as viewedin the figure, and is shared by two adjacent sharing units. Thus,arrangement of the selection transistor TR14 and the amplificationtransistor TR13 in FIG. 11 is inverted to right and left in the sharingunits of FIG. 12 so that the selection transistors TR14 of both sharingunits can be easily coupled to the same vertical signal line VSLprovided at the boundary between two sharing units of FIG. 12.

As in the case where the source/drain (S/D) is shared by the sharingunits adjacent to each other in the horizontal direction, the verticalsignal line VSL is further shared in the layout of the solid-state imagesensor of FIG. 12, and therefore, the L lengths of the selectiontransistors TR14 and the amplification transistors TR13 can be ensured.

Eighth Embodiment

<Layout of Solid-State Image Sensor Provided with Reset Transistor andDummy Transistor Thereof>

The example where the reset transistor TR11 is provided for the sharingunit including the total of eight pixels, i.e., the sharing unit inwhich the pixels of 2×4 in four OCCFs share the FD, has been describedabove. However, in order to improve symmetry in the horizontal directionand reduce photo response non-uniformity, a reset transistor TR11 may beprovided on a source/drain (S/D) adjacent to a lower end portion of oneof right and left PDs of a lowermost OCCF, and a dummy transistor havingthe same configuration as that of the reset transistor TR11 may beprovided on the source/drain (S/D) adjacent to the other PD.

FIG. 13 illustrates the layout of a solid-state image sensor configuredas follows: the reset transistor TR11 is, instead of the resettransistor TR11 of the solid-state image sensor of FIG. 10, provided onthe source/drain (S/D) adjacent to a lower end portion of a PD 7 as oneof the right and left PDs of the lowermost OCCF, and the resettransistor (the dummy transistor) TR11 having the same configuration asthat of the reset transistor TR11 is provided on the source/drain (S/D)adjacent to a PD 8 as the other PD. As long as only one of the right andleft transistors functions as the reset transistor TR11, the othertransistor may be the same dummy transistor as the reset transistorTR11.

With such a layout, the horizontal symmetry of the pixels forming thesharing units can be improved, and photo response non-uniformity can bereduced. Note that even when the reset transistor TR11 of each of thesolid-state image sensors of FIGS. 11 and 12 as described above includestwo reset transistors TR11 (any of these transistors may be a dummytransistor) as illustrated in FIG. 13, similar advantageous effects canbe provided.

Ninth Embodiment

<Layout of Solid-State Image Sensor in Sharing of FD by 3Tr. Type Pixelsof 2×4>

The layout of the solid-state image sensor configured such that the FDis shared by the 4Tr. type pixels of 2×4 has been described above, butthe FD may be shared by 3Tr. type pixels of 2×4.

FIG. 14 illustrates the layout of a solid-state image sensor configuredsuch that an FD is shared by 3Tr. type pixels of 2×4. Note that in thelayout of the solid-state image sensor of FIG. 14, the same names andthe same reference numerals are used to represent equivalent elements ina configuration having the same functions as those of the configurationin the layout of the solid-state image sensor of FIG. 10, anddescription thereof will be optionally omitted.

That is, the layout of the solid-state image sensor of FIG. 14 isdifferent from the layout of the solid-state image sensor of FIG. 10 inthat a reset transistor TR1, a transfer transistor TR2, and anamplification transistor TR3 are provided instead of the resettransistor TR11, the transfer transistor TR12, the amplificationtransistor TR13, and the selection transistor TR14.

Thus, each of transfer transistors TR2-1 to TR2-8 is provided at acorresponding position of PD 1 to PD 8, and the amplification transistorTR3 is, instead of the amplification transistor TR13 and the selectiontransistor TR14, provided at a center position of the boundary betweenan upper OCCF for R and a lower OCCF for Gb. Moreover, the resettransistor TR1 is provided instead of the reset transistor TR11.

According to the layout of the solid-state image sensor of FIG. 14, theL length of the amplification transistor TR3 can be easily ensured, andtherefore, worsening of random noise can be suppressed. Further, thepositions of well contacts C1 to C4 are changeable as in the layout ofthe solid-state image sensors described with reference to FIGS. 4 and 7,and are not limited to arrangement in the solid-state image sensors ofFIGS. 10 and 11.

Tenth Embodiment

<Layout of Solid-State Image Sensor in Sharing of FD by 4Tr. Type Pixelsof 8×1>

The example where the sharing unit for sharing the FD includes the totalof eight pixels of the different OCCFs, i.e., the total of four OCCFs of1×4, has been described above. However, the layout of the plurality ofpixels forming the sharing unit may be other layout than above, and forexample, the sharing unit for sharing an FD may include pixels of 8×1.

FIG. 15 illustrates the layout of a solid-state image sensor configuredsuch that the sharing unit for sharing the FD includes the pixels of8×1.

As in the case of the solid-state image sensor of FIG. 4, two PDselongated in the vertical direction are, for each on-chip color filter(OCCF), arranged in the horizontal direction in FIG. 15, and these twoPDs continuously arranged in the horizontal direction form a squareregion.

More specifically, of the OCCFs with a Bayer array of Gb, R, B, Grprovided in this order of the upper left side, the lower left side, theupper right side, the lower right side as viewed in FIG. 15, the OCCFsfor R, Gr arranged adjacent to each other in the horizontal direction inthe lower row as viewed in the figure are repeated twice, and therefore,these four OCCFs in total form one of sharing units. Similarly, of theOCCFs with the Bayer array of Gb, R, B, Gr provided in this order fromthe left side to the right side, the OCCFs for Gb, B arranged adjacentto each other in the horizontal direction in the upper row as viewed inthe figure are repeated twice in a row above the row of the OCCFs for R,Gr, and therefore, these four OCCFs in total form the other sharingunit. Then, the row in which the one sharing unit is repeatedly arrangedin the horizontal direction and the row in which the other sharing unitis repeatedly arranged in the horizontal direction are alternatelyarranged.

For the OCCF for R on the left side in one of the sharing units,rectangular PD 1, PD 2 whose vertical length is longer than thehorizontal length are provided. Similarly, the OCCF for Gr on the rightside of the OCCF for R is provided with PD 3, PD 4, another OCCF for Ron the right side of the OCCF for Gr is provided with PD 5, PD 6, andanother OCCF for Gr at the right end of the sharing unit is providedwith PD 7, PD 8.

That is, in FIG. 15, a common FD is provided for the total of eightpixels, each of the total of four OCCFs of four in the horizontaldirection×one in the vertical direction being provided with two pixelsarranged in the horizontal direction.

Further, transfer transistors TR12-1, TR12-2 are provided respectivelyat the corners of the PD 1, PD 2 such that the corners respectivelycontact end portions of a square FD (T1) in the horizontal direction,the square FD being provided at a center position of the boundary of anupper end of each OCCF for R, Gr, R, Gr. Further, transfer transistorsTR12-3, TR12-4 are provided respectively at the corners of the PD 3, PD4 such that the corners respectively contact end portions of a square FD(T2). Further, transfer transistors TR12-5, TR12-6 are providedrespectively at the corners of the PD 5, PD 6 such that the cornersrespectively contact end portions of a square FD (T3). In addition,transfer transistors TR12-7, TR12-8 are provided respectively at thecorners of the PDs 7, 8 such that the corners respectively contact endportions of a square FD (T4). Moreover, the terminals T1 to T4 arecoupled to the same FD through the same line, and therefore, the same FDis shared by the PD 1 to PD 8.

Further, at the lower end of the sharing unit at the boundary betweenadjacent right and left ones of the OCCFs for R, Gr, R, Gr, a resettransistor TR11, an amplification transistor TR13, and a selectiontransistor TR14 are, in this order from the left side, provided toextend across an S/D (a source/drain) such that the transistors TR11,TR13, TR14 are coupled to the line coupled to the FD together with thecommon terminals T1 to T4.

Further, well contacts C1 to C5 are provided at the upper end corners ofthe OCCFs for R, Gr, R, Gr at the boundary between adjacent right andleft ones of these OCCFs.

According to the layout of the solid-state image sensor of FIG. 15, alength in the horizontal direction as viewed in the figure can be easilyensured, and therefore, the L lengths of the reset transistor TR11, theamplification transistor TR13, and the selection transistor TR14 can beeasily increased. Thus, worsening of random noise can be suppressed.

Moreover, in each sharing unit of the layout of the solid-state imagesensor of FIG. 15, the same FD is shared by two OCCFs for the samecolor. Thus, FD addition is available for pixel signals of the pixelsfor the same color, and therefore, a dynamic range can be expanded.Further, in the case of providing a plurality of vertical signal linesVSL in a BEOL layout, a sufficient space in the horizontal direction isensured, and therefore, interference due to a capacitive couplingbetween adjacent ones of the vertical signal lines VSL can be reduced.

Eleventh Embodiment

<Layout of Solid-State Image Sensor Configured Such that FD is Shared by4Tr. Type Pixels of 8×1 and Dummy Transistor is Provided>

The example where the reset transistor TR11, the amplificationtransistor TR13, and the selection transistor TR14 are provided at thehorizontal boundary of the lower ends of four OCCFs in the sharing unitincluding the pixels of 8×1 has been described above. However, a dummytransistor having similar configuration to that of any of the resettransistor TR11, the amplification transistor TR13, and the selectiontransistor TR14 and not functioning as a transistor may be added, and atransistor may be formed at a lower end of each of four OCCFs. In thismanner, symmetry may be improved.

In the layout of a solid-state image sensor of FIG. 16, the same dummytransistor as any of the reset transistor TR11, the amplificationtransistor TR13, and the selection transistor TR14 in the layout of thesolid-state image sensor of FIG. 15 may be provided in addition to thesetransistors of FIG. 15 to improve symmetry in transistor arrangement.

More specifically, the solid-state image sensor of FIG. 16 is configuredsuch that the reset transistor TR11, the dummy transistor TRD, theamplification transistor TR13, and the selection transistor TR14 areprovided respectively at the centers of lower ends of OCCFs for R, Gr,R, Gr.

With such a configuration, symmetry in the horizontal direction can beimproved, and photo response non-uniformity can be improved.

Twelfth Embodiment

<Layout of Solid-State Image Sensor in Sharing of FD by 3Tr. Type Pixelsof 8×1>

The layout of the solid-state image sensor employing the sharing unitincluding the 4Tr. type pixels of 8×1 has been described above, but a3Tr. type solid-state image sensor may be employed instead of the 4Tr.type solid-state image sensor.

FIG. 17 illustrates the layout of the 3Tr. type solid-state image sensoremploying a sharing unit including pixels of 8×1. Note that in thelayout of the solid-state image sensor of FIG. 17, the same names andthe same reference numerals are used to represent equivalent elements ina configuration having the same functions as those of the configurationin the layout of the solid-state image sensor of FIG. 16, anddescription thereof will be optionally omitted.

That is, the layout of the solid-state image sensor of FIG. 17 isdifferent from the layout of the solid-state image sensor of FIG. 16 inthe following points: transfer transistors TR2-1 to TR2-8 are providedinstead of the transfer transistors TR12-1 to TR12-8 providedrespectively at the PD 1 to PD 8; and a reset transistor TR1 and anamplification transistor TR3 are, in this order from the left side,provided to extend across an S/D, each transistor being provided at OCCFlower ends at the boundary between two horizontally-arranged OCCFs forR, Gr included in four OCCFs for R, Gr, R, Gr arranged in the horizontaldirection to form a sharing unit.

According to the configuration of the solid-state image sensor of FIG.17, the L lengths of the reset transistor TR1 and the amplificationtransistor TR3 can be easily ensured, and worsening of random noise canbe suppressed.

Thirteenth Embodiment

<Layout of Solid-State Image Sensor in Sharing of FD by Other PixelNumber Than Eight Pixels>

The solid-state image sensor configured such that the FD is shared bythe sharing unit including eight pixels of the different OCCFs has beendescribed above. However, the solid-state image sensor may be configuredsuch that an FD is shared by other pixel number than above, such pixelsforming different OCCFs.

For example, a solid-state image sensor configured such that a sharingunit for sharing an FD by the total of four pixels, i.e., 4Tr. typepixels of 2×2, may have a layout as illustrated in FIG. 18.

More specifically, in the layout of the solid-state image sensor of FIG.18, two OCCFs arranged for Gb, R of a Bayer array in this order from theupper side to the lower side in the vertical direction form one ofsharing units. Similarly, two OCCFs arranged for B, Gr of the Bayerarray in the order from the upper side to the lower side in the verticaldirection forms the other sharing unit in a column next to the column ofthe OCCFs for Gb, R. Then, the column in which the one sharing unitrepeatedly is arranged in the vertical direction and the column in whichthe other sharing unit repeatedly is arranged in the vertical directionare alternately arranged.

For the OCCF for Gb in one of the sharing units, rectangular PD 1, PD 2whose vertical length is longer than the horizontal length are provided.Similarly, the OCCF for R is provided with PD 3, PD 4.

That is, in FIG. 18, a common FD is provided for the total of fourpixels, each of the total of two OCCFs of one in the horizontaldirection×two in the vertical direction being provided with two pixelsarranged in the horizontal direction.

Further, transfer transistors TR12-1 to TR12-4 are provided respectivelyat the corners of the PD 1 to PD 4 such that the corners respectivelycontact the positions of a square FD (T1) facing the corners, the squareFD being provided at a center position of the boundary between the upperOCCF for Gb and the lower OCCF for R.

Further, at a lower end of the OCCF for R, a reset transistor TR11, anamplification transistor TR13 and a selection transistor TR14 are, inthis order from the left side, provided to extend across an S/D (asource/drain) such that the transistors TR11, TR13 and TR14 are coupledto a line coupled to the common square FD (T1).

Well contacts C1, C2 are provided respectively at the corners of theOCCFs for Gb, R at the boundary between these OCCFs.

According to the layout of the solid-state image sensor of FIG. 18, itis difficult to ensure a length in the horizontal direction as viewed inthe figure, and for this reason, it is difficult to reduce the influenceof random noise. However, a conversion efficiency can be improved.

Further, drive lines for HDR driving can be easily arranged in a BEOLlayout, and the influence of parasitic capacitance due to a capacitivecoupling between adjacent ones of the drive lines can be reduced.

Note that the number of pixels sharing the FD may be other number thanabove. For example, such a number may be eight or four pixels, and thesharing unit may include eight or four pixels of four OCCFs arrangedlonger in the vertical or horizontal direction.

The example where the FD is shared by the sharing unit including theplurality of pixels of the different on-chip color filters (OCCFs) inthe configuration of arranging the plurality of pixels in the same OCCFhas been described above. However, an FD may be shared by a sharing unitincluding a plurality of pixels of different on-chip lenses (OCLs) inthe configuration of arranging a plurality of pixels in the same OCL.Alternatively, the configuration may be employed, in which an OCCF andan OCL are stacked on each other.

<Examples of Application to Electronic Equipment>

Each of the above-described solid-state image sensors is applicable tovarious types of electronic equipment including imaging devices such asdigital still cameras and digital video cameras, portable phones havingan imaging function, and other types of equipment having an imagingfunction, for example.

FIG. 19 is a block diagram of a configuration example of an imagingdevice as electronic equipment to which the present technology isapplied.

The imaging device 201 illustrated in FIG. 19 includes an optical system202, a shutter device 203, a solid-state image sensor 204, a controlcircuit 205, a signal processing circuit 206, a monitor 207, and amemory 208. The imaging device 201 is configured to acquire a stillimage and a video image.

The optical system 202 includes a lens or a plurality of lenses, and isconfigured to guide light (incident light) from an object to thesolid-state image sensor 204 to form an image on a light receivingsurface of the solid-state image sensor 204.

The shutter device 203 is disposed between the optical system 202 andthe solid-state image sensor 204, and is configured to control a lightirradiation period and a light shielding period for the solid-stateimage sensor 204 according to control of the control circuit 205.

The solid-state image sensor 204 includes a package with theabove-described solid-state image sensor. The solid-state image sensor204 is configured to accumulate, for a certain period, signal chargeaccording to the light used to form the image on the light receivingsurface via the optical system 202 and the shutter device 203. Thesignal charge accumulated in the solid-state image sensor 204 istransferred according to a drive signal (a timing signal) supplied fromthe control circuit 205.

The control circuit 205 is configured to output the drive signal forcontrolling transfer operation of the solid-state image sensor 204 andshutter operation of the shutter device 203 to drive the solid-stateimage sensor 204 and the shutter device 203.

The signal processing circuit 206 is configured to perform various typesof signal processing for the signal charge output from the solid-stateimage sensor 204. An image (image data) obtained by the signalprocessing of the signal processing circuit 206 is supplied anddisplayed on the monitor 207, or is supplied and stored (recorded) inthe memory 208.

Even in the imaging device 201 configured as described above, theabove-described solid-state image sensor is, instead of the solid-stateimage sensor 204, applicable to realize imaging with low noise acrossall pixels.

<Use Examples of Solid-State Image Sensor>

FIG. 20 is a diagram of use examples of each of the above-describedsolid-state image sensors.

Each of the above-described solid-state image sensors can be used asfollows in various cases of sensing light such as visible light,infrared light, ultraviolet light, and X-rays:

The device configured to shoot an image for entertainment, such asdigital cameras and portable devices with a camera function;

the device for transportation for the purpose of, e.g., safe drivingsuch as automatic stop and driver's state recognition, such asin-vehicle sensors configured to shoot, e.g., images of the front, back,periphery, and inside of an automobile, monitoring cameras configured tomonitor a running vehicle and a road, and distance measurement sensorsconfigured to measure, e.g., the distance between vehicles;

the device for home appliances such as TV sets, refrigerators, andair-conditioners for the purpose of shooting images of user's gesturesto perform equipment operation according to such gestures;

the device for medical treatment and health care, such as endoscopes andthe devices configured to shoot images of blood vessels by receiving ofinfrared light;

the device for security, such as surveillance cameras for crimeprevention and cameras for personal authentication;

the device for beauty care, such as a skin checker configured to shootan image of the skin and microscopes configured to shoot an image of thescalp;

the device for sports, such as action cameras and wearable cameras forthe purpose of, e.g., sports; and

the device for agriculture, such as cameras configured to monitor thestate of a field and crops.

Note that the present technology may have the following configurations.

-   (1) A solid-state image sensor including:

at least either of on-chip color filters (OCCFs) configured to extractlight having a predetermined wavelength from incident light or on-chiplenses (OCLs) configured to collect the incident light;

photo diodes configured to use, as incident light, at least either ofthe light having the predetermined wavelength and extracted by the OCCFsor the light collected by the OCLs to generate, for each pixel unit,charge corresponding to an amount of the incident light by aphotoelectric effect; and

a floating diffusion (FD) configured to accumulate the charge generatedby the photo diodes to apply voltage corresponding to the accumulatedcharge to a gate of an amplification transistor,

wherein, in a configuration in which a plurality of pixels are arrangedwith respect to at least either of one of the OCCFs or one of the OCLs,the FD is shared by a sharing unit including a plurality of pixels, theplurality of pixels including pixels of at least either of differentOCCFs or different OCLs.

-   (2) The solid-state image sensor according to (1), wherein

the photo diodes of two pixels are arranged with respect to at leasteither of one of the OCCFs or one of the OCLs.

-   (3) The solid-state image sensor according to (1) or (2), wherein

the sharing unit includes the pixels corresponding to at least either ofthe OCCFs or the OCLs adjacent to each other in a horizontal direction.

-   (4) The solid-state image sensor according to (3), wherein

the sharing unit includes the pixels corresponding to at least any onesof two OCCFs, four OCCFs, two OCLs, and four OCLs adjacent to each otherin the horizontal direction.

-   (5) The solid-state image sensor according to (1) or (2), wherein

the sharing unit includes the pixels corresponding to at least either ofthe OCCFs or the OCLs adjacent to each other in a vertical direction.

-   (6) The solid-state image sensor according to (5), wherein

the sharing unit includes the pixels corresponding to at least any onesof two OCCFs, four OCCFs, two OCLs, and four OCLs adjacent to each otherin the vertical direction.

-   (7) The solid-state image sensor according to (1) or (2), wherein

the sharing unit includes the pixels corresponding to at least either ofthe OCCFs or the OCLs adjacent to each other in horizontal and verticaldirections.

-   (8) The solid-state image sensor according to (7), wherein

the sharing unit includes the pixels corresponding to at least either ofthe OCCFs or the OCLs adjacent to each other such that there are twoOCCFs or two OCLs in the horizontal direction and two OCCFs or two OCLsin the vertical direction.

-   (9) The solid-state image sensor according to any of (1) to (8),    wherein

the sharing unit includes the pixels corresponding to at least either ofthe OCCFs or the OCLs extracting light having an identical wavelength.

-   (10) The solid-state image sensor according to any of (1) to (9),    further including:

a reset transistor;

a transfer transistor; and

the amplification transistor.

-   (11) The solid-state image sensor according to any of (1) to (10),    further including:

a reset transistor;

a transfer transistor;

the amplification transistor;

a selection transistor.

-   (12) The solid-state image sensor according to (11), wherein

a dummy transistor is disposed at such a position that arrangementintervals with respect to the reset transistor, the amplificationtransistor, and the selection transistor are in symmetrical positions inan arrangement direction of the reset transistor, the amplificationtransistor, and the selection transistor.

-   (13) The solid-state image sensor according to any of (1) to (12),    further including:

a vertical signal line configured to transfer a pixel signal output fromthe amplification transistor,

wherein the vertical signal line is shared by the sharing units.

-   (14) The solid-state image sensor according to any of (1) to (13),    wherein

a source/drain is shared by the sharing units.

-   (15) An imaging device including:

at least either of on-chip color filters (OCCFs) configured to extractlight having a predetermined wavelength from incident light or on-chiplenses (OCLs) configured to collect the incident light;

photo diodes configured to use, as incident light, at least either ofthe light having the predetermined wavelength and extracted by the OCCFsor the light collected by the OCLs to generate, for each pixel unit,charge corresponding to an amount of the incident light by aphotoelectric effect; and

a floating diffusion (FD) configured to accumulate the charge generatedby the photo diodes to apply voltage corresponding to the accumulatedcharge to a gate of an amplification transistor,

wherein, in a configuration in which a plurality of pixels are arrangedwith respect to at least either of one of the OCCFs or one of the OCLs,the FD is shared by a sharing unit including a plurality of pixels, theplurality of pixels including pixels of at least either of differentOCCFs or different OCLs.

-   (16) Electronic equipment including:

at least either of on-chip color filters (OCCFs) configured to extractlight having a predetermined wavelength from incident light or on-chiplenses (OCLs) configured to collect the incident light;

photo diodes configured to use, as incident light, at least either ofthe light having the predetermined wavelength and extracted by the OCCFsor the light collected by the OCLs to generate, for each pixel unit,charge corresponding to an amount of the incident light by aphotoelectric effect; and

a floating diffusion (FD) configured to accumulate the charge generatedby the photo diodes to apply voltage corresponding to the accumulatedcharge to a gate of an amplification transistor,

wherein, in a configuration in which a plurality of pixels are arrangedwith respect to at least either of one of the OCCFs or one of the OCLs,the FD is shared by a sharing unit including a plurality of pixels, theplurality of pixels including pixels of at least either of differentOCCFs or different OCLs.

REFERENCE SIGNS LIST

-   TR1 Reset transistor-   TR2, TR2-1 to TR2-8 Transfer transistor-   TR3 Amplification transistor-   TR11 Reset transistor-   TR12, TR12-1 to TR12-8 Transfer transistor-   TR13 Amplification transistor-   TR14 Selection transistor-   PD, PD1 to PD8 Photo diode-   FD Floating diffusion

The invention claimed is:
 1. An electronic apparatus comprising: an optical system including a lens; an image sensor configured to receive light transmitted through the lens; a control circuit configured to drive an operation of the image sensor; a signal processing circuit configured to perform signal processing on signals output from the image sensor, wherein the image sensor comprises: a plurality of sharing units, wherein a first sharing unit of the plurality of sharing units includes: eight photoelectric conversion regions; four color filters arranged in a 2×2 matrix, wherein each of the four color filters is disposed in a stack with an on-chip lens and is arranged at a light-incident side of two photoelectric conversion regions of the eight photoelectric conversion regions; a floating diffusion coupled to each of the eight photoelectric conversion regions; shared transistors including a single amplification transistor having a gate coupled to the floating diffusion, the shared transistors arranged in a horizontal direction; and a first vertical signal line coupled to the single amplification transistor, the first vertical signal line extending along a vertical direction, wherein the floating diffusion includes a first terminal and a second terminal, wherein the shared transistors are arranged in a first row and wherein the first terminal and the second terminal are arranged in a second row, wherein at least two color filters of the four color filters arranged along the horizontal direction are configured to extract light having different wavelength ranges, wherein the shared transistors further include a reset transistor and a selection transistor, and wherein the first vertical signal line is coupled to the single amplification transistor via the selection transistor.
 2. The electronic apparatus according to claim 1, wherein the image sensor further comprises: a first well contact and a second well contact, wherein the reset transistor, the selection transistor, and the single amplification transistor are arranged between the first well contact and the second well contact, and wherein the single amplification transistor is arranged between the reset transistor and the selection transistor in the first row.
 3. An electronic apparatus comprising: an optical system including a lens; an image sensor configured to receive light transmitted through the lens; a control circuit configured to drive an operation of the image sensor; a signal processing circuit configured to perform signal processing on signals output from the image sensor, wherein the image sensor comprises: a plurality of sharing units, wherein a first sharing unit of the plurality of sharing units includes: eight photoelectric conversion regions; four color filters arranged in a 2×2 matrix, wherein each of the four color filters is disposed in a stack with an on-chip lens and is arranged at a light-incident side of two photoelectric conversion regions of the eight photoelectric conversion regions; a floating diffusion coupled to each of the eight photoelectric conversion regions; shared transistors including a single amplification transistor having a gate coupled to the floating diffusion, the shared transistors arranged in a horizontal direction; and a first vertical signal line coupled to the single amplification transistor, the first vertical signal line extending along a vertical direction, wherein the floating diffusion includes a first terminal and a second terminal, wherein the shared transistors are arranged in a first row and wherein the first terminal and the second terminal are arranged in a second row, wherein at least two color filters of the four color filters arranged along the horizontal direction are configured to extract light having different wavelength ranges, wherein each photoelectric conversion region of the eight photoelectric conversion regions is provided such that a length of the photoelectric conversion region in the vertical direction is longer than a length of the photoelectric conversion region in the horizontal direction.
 4. An electronic apparatus comprising: an optical system including a lens; an image sensor configured to receive light transmitted through the lens; a control circuit configured to drive an operation of the image sensor; a signal processing circuit configured to perform signal processing on signals output from the image sensor, wherein the image sensor comprises: a plurality of sharing units, wherein a first sharing unit of the plurality of sharing units includes: eight photoelectric conversion regions; four color filters arranged in a 2×2 matrix, wherein each of the four color filters is disposed in a stack with an on-chip lens and is arranged at a light-incident side of two photoelectric conversion regions of the eight photoelectric conversion regions; a floating diffusion coupled to each of the eight photoelectric conversion regions; shared transistors including a single amplification transistor having a gate coupled to the floating diffusion, the shared transistors arranged in a horizontal direction; and a first vertical signal line coupled to the single amplification transistor, the first vertical signal line extending along a vertical direction, wherein the floating diffusion includes a first terminal and a second terminal, wherein the shared transistors are arranged in a first row and wherein the first terminal and the second terminal are arranged in a second row, wherein at least two color filters of the four color filters arranged along the horizontal direction are configured to extract light having different wavelength ranges, wherein four of the eight photoelectric conversion regions are arranged around the first terminal of the floating diffusion and are coupled to the first terminal of the floating diffusion, and another four of the eight photoelectric conversion regions are arranged around the second terminal of the floating diffusion and are coupled to the second terminal of the floating diffusion.
 5. An electronic apparatus comprising: an optical system including a lens; an image sensor configured to receive light transmitted through the lens; a control circuit configured to drive an operation of the image sensor; a signal processing circuit configured to perform signal processing on signals output from the image sensor, wherein the image sensor comprises: a plurality of sharing units, wherein a first sharing unit of the plurality of sharing units includes: eight photoelectric conversion regions; four color filters arranged in a 2×2 matrix, wherein each of the four color filters is disposed in a stack with an on-chip lens and is arranged at a light-incident side of two photoelectric conversion regions of the eight photoelectric conversion regions; a floating diffusion coupled to each of the eight photoelectric conversion regions; shared transistors including a single amplification transistor having a gate coupled to the floating diffusion, the shared transistors arranged in a horizontal direction; and a first vertical signal line coupled to the single amplification transistor, the first vertical signal line extending along a vertical direction, wherein the floating diffusion includes a first terminal and a second terminal, wherein the shared transistors are arranged in a first row and wherein the first terminal and the second terminal are arranged in a second row, wherein at least two color filters of the four color filters arranged along the horizontal direction are configured to extract light having different wavelength ranges, wherein the image sensor further comprises: eight transfer transistors, each of which is coupled to one of the eight photoelectric conversion regions and the floating diffusion; a first transfer control signal line extending along the horizontal direction and electrically connected to a gate of a first transfer transistor of the eight transfer transistors; a second transfer control signal line extending along the horizontal direction and electrically connected to a gate of a second transfer transistor of the eight transfer transistors; a third transfer control signal line extending along the horizontal direction and electrically connected to a gate of a third transfer transistor of the eight transfer transistors; and a fourth transfer control signal line extending along the horizontal direction and electrically connected to a gate of a fourth transfer transistor of the eight transfer transistors.
 6. An electronic apparatus comprising: an optical system including a lens; an image sensor configured to receive light transmitted through the lens; a control circuit configured to drive an operation of the image sensor; a signal processing circuit configured to perform signal processing on signals output from the image sensor, wherein the image sensor comprises: a plurality of sharing units, wherein a first sharing unit of the plurality of sharing units includes: eight transfer transistors; four color filters arranged in a 2×2 matrix, wherein each of the four color filters is disposed in a stack with an on-chip lens and is arranged at a light-incident side of two transfer transistors of the eight transfer transistors; a floating diffusion coupled to each of the eight transfer transistors; shared transistors including a single amplification transistor having a gate coupled to the floating diffusion, the shared transistors arranged in a horizontal direction; and a first vertical signal line coupled to the single amplification transistor, the first vertical signal line extending along a vertical direction, wherein the floating diffusion includes a first terminal and a second terminal, wherein the shared transistors are arranged in a first row and wherein the first terminal and the second terminal are arranged in a second row, and wherein at least two color filters of the four color filters arranged along the horizontal direction are configured to extract light having different wavelength ranges.
 7. The electronic apparatus according to claim 6, wherein the image sensor further comprises: a second vertical signal line coupled to the single amplification transistor, the second vertical signal line extending in the vertical direction.
 8. The electronic apparatus according to claim 6, wherein the first vertical signal line is coupled to the single amplification transistor via a selection transistor.
 9. The electronic apparatus according to claim 6, wherein the shared transistors further include a reset transistor and a selection transistor, and wherein the reset transistor, the selection transistor and the single amplification transistor are arranged in the first row.
 10. The electronic apparatus according to claim 9, wherein the image sensor further comprises: a first well contact and a second well contact, wherein the reset transistor, the selection transistor, and the single amplification transistor are arranged between the first well contact and the second well contact.
 11. The electronic apparatus according to claim 9, wherein the single amplification transistor is arranged between the reset transistor and the selection transistor in the first row.
 12. The electronic apparatus according to claim 11, wherein the reset transistor, the single amplification transistor, and the selection transistor are arranged in order along the horizontal direction in the first row.
 13. The electronic apparatus according to claim 6, wherein each photoelectric conversion region of the eight photoelectric conversion regions is provided such that a length of the photoelectric conversion region in the vertical direction is longer than a length of the photoelectric conversion region in the horizontal direction.
 14. The electronic apparatus according to claim 6, wherein the four color filters include a first color filter configured to extract light having a first wavelength range, a second color filter configured to extract light having a second wavelength range, a third color filter configured to extract light having a third wavelength range, and a fourth color filter configured to extract light having a fourth wavelength range, wherein the first color filter and the fourth color filter are arranged in a diagonal direction in the 2×2 matrix, the first wavelength range, the second wavelength range and third wavelength range are different, and the first wavelength range and the fourth wavelength range are substantially the same.
 15. The electronic apparatus according to claim 6, wherein the image sensor further comprises: a first transfer control signal line extending along the horizontal direction and electrically connected to a gate of a first transfer transistor of the eight transfer transistors; a second transfer control signal line extending along the horizontal direction and electrically connected to a gate of a second transfer transistor of the eight transfer transistors; a third transfer control signal line extending along the horizontal direction and electrically connected to a gate of a first transfer transistor of the eight transfer transistors; and a fourth transfer control signal line extending along the horizontal direction and electrically connected to a gate of a second transfer transistor of the eight transfer transistors, wherein the first transfer transistor, the second transfer transistor, the third transfer transistor and the fourth transfer transistor are arranged in order along the horizontal direction along a same pixel row.
 16. The electronic apparatus according to claim 15, wherein the image sensor further comprises: a second set of eight transfer transistors arranged relative to the eight transfer transistors in the horizontal direction; a second floating diffusion coupled to each of the transfer transistors in the second set of eight transfer transistors; a fifth transfer control signal line extending along the horizontal direction and electrically connected to a gate of a fifth transfer transistor of the second set of eight transfer transistors; a sixth transfer control signal line extending along the horizontal direction and electrically connected to a gate of a sixth transfer transistor of the second set of eight transfer transistors, wherein, the third transfer control signal line is electrically connected to a gate of a seventh transfer transistor of the second set of eight transfer transistors, the fourth transfer control signal line is electrically connected to a gate of an eighth transfer transistor of the second set of eight transfer transistors, and the first transfer transistor, the second transfer transistor, the third transfer transistor, the fourth transfer transistor, the fifth transfer transistor, the sixth transfer transistor, the seventh transfer transistor and the eighth transfer transistor are arranged in order along the horizontal direction along a same pixel row. 